
The prediction of the GW spectrum in the naHEFT was investigated in Ref. [1]}.
To examine parameter regions where GWs can be detected at LISA and DECIGO, we use the signal-to-noise ratio for the observation of the GW spectrum, which is discussed in Ref. [2]}.
The criterion is such that the signal-to-noise ratio for the GW spectrum is larger than ten, which is adopted in our later analysis.
